Previous oauth2 (code.google.com/p/goauth2/oauth) still used in:
third_party/github.com/tgulacsi/picago
pkg/importer/picasa
pkg/importer/foursquare
Final cleanup in a subsequent CL.
Change-Id: I805d81fcaa651e03a17823c78abe5040d51346c3
Also, delete my old gce package from third_party and only use the
google metadata package (which my gce package became, and which was
also already vendored into third_party)
Fixes#596
Change-Id: I64fd6f1e9dc6f433466f91f81efd2ecbf039334f
mpl